He's talking out of his ARSE!
All vehicles as far as I know are given a chasis number before they are even welded into a shell. It's from the chasis number that the rest of the parts are allocated to make it up to the correct spec.
As an example at the MINI plant in Cowley the CHasis number is read by a reader which will then specify which engine should be fitted, which seats etc and as it goes down the line the correct parts are applied.
THe only way I could see this not happening is if VW use some kind of build number for the car and then apply the chasis number last. Seems a wierd way of doing it becuase it duplicates effort. Besides which if it was built in August and still has no chasis number what's going on? It;s hardly going to be stuck on the line somewhere waiting for a fualty robot to mark the number? Also there is no way cars would be given a chasis number in a seperate process weeks after they were built.
I smell large amounts of bull sh!t eminating from your dealership!
Nick